Weightlifting, also known as bodybuilding, is a form of exercise that results in muscular endurance and strength. Strength is not measured by the size or bulk of muscles. Instead strength is measured by the amount of weight lifted and the duration of exercises. Muscle strength increases with increased resistance (heavier weights), repetitions, number of sets and intensity (i.e. reducing recover periods between sets).

Most weight training involves isotonic exercises. Isotonic muscle training involves contractions where tension is equal throughout the range of motion.

Isometric muscle training contraction of a muscle against an immovable force. For instance, muscles will flex and hold a stationary position when an individual pushes against a wall. This form is used most commonly in patients undergoing rehabilitation or physical therapy.

Isokinetic muscle training is a type of contraction where the speed of movement is fixed and resistance varies with the force exerted. In other words, resistance the harder an individual pushes or pulls, the more resistance is felt.

Bodybuilding and weightlifting are not interchangeable terms. Bodybuilders focus on gaining bulk and increasing the size of muscles while weightlifters focus on the strength and power of the muscles. While weightlifters' muscles often appear smaller than bodybuilders', they can lift heavier weights for longer periods of time.

Strength endurance: Strength endurance is achieved by repeating exercises for the highest possible number of repetitions in total, with resistance representing 40-60% of maximum weight that can be lifted.

Between workouts: After completing a weightlifting workout, wait 24-48 hours before lifting with the same muscles.

Postural technique:

Head should be parallel to the ground and centered over shoulders.

Bring the chest up and relax the shoulders.

Tighten the abdomen muscles.

Align the knees with the toes.

The knees should not be locked. Always keep them slightly bent.

Feet should be spaced comfortably apart (usually hip width).

When standing, body weight should be centered at the mid points of feet.

Free weights (barbells, dumbbells, etc.) are used to strengthen both the targeted muscles and stabilizing muscles (such as the abdomen and back).

The stabilizing muscles help stabilize the body, support limbs and maintain posture during a lift. Therefore, lifting free weights improves coordination by improving the neuromuscular pathways that connect muscles to the central nervous system.

Free weight exercises also allow lifters to mimic real life or sports-specific motions. Without the restrictive "guiding" of weight machines, the user of free weights can design an exercise that will closely mimic the real life motion that needs to be strengthened.

Most free weight exercises are performed in a standing position.

A spotter is recommended when lifting heavy weights. Complete control must be maintained when lifting heavy free weights to avoid injury to muscles and joints.

The concept of "momentum" is also a safety issue. When free weights are in the eccentric or return portion of the exercise, the weight has built up momentum that muscles must overcome. This puts stress on the muscles, joints and connective tissues (tendons, ligaments). Using the proper amount of weight and establishing good technique are essential when using free weights.

Machine weights are used to isolate individual muscles. Many different machines of varying quality are available for strength training of any muscle group.

Machine weights guide and control the path of resistance. Therefore, there is less danger of being trapped, pinched or otherwise injured than there is with free weights.

Machine weights may be lifted safety without a spotter. Lifters must make sure the machine is properly fitted (i.e. chair height) to avoid injury. Appropriate weight and good technique are essential when lifting machine weights. Follow additional safety instructions posted on individual machines.

Circuit training generally involves 6-10 strength exercises that are completed one after another.

Each exercise is performed for a specific number of repetitions or time period (usually about one minute) before moving to the next exercise. There is a brief resting period between exercises, usually about 30 seconds to one minute.

One circuit is the completion of all exercises. The circuit is usually repeated 2-6 times, with a 3-5 minute recover period between circuits.

Workouts are tailored to individuals. Circuit training can involve endurance, strength and agility workouts. Exercises should be chosen carefully and include multiple muscle groups.

The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.